Blood collection is always important, particularly in times of emergency (immediate use), but whole blood may only be stored for about 30 days before it is “outdated”. For long term storage, the ability to separate the whole blood into its major components (white blood cells, platelets, red blood cells and plasma) is of paramount importance because the long term storage condition for each component is different in terms of temperature and storage media. The most important component separations occurring after collection is the separation of red blood cells (RBC), white blood cells (WBC), platelets, and plasma from one another. Within the WBC it is sometimes important to separate the granulocytes from the lymphocytes. After separation and extraction of particular components, a fraction of the blood may be returned to the patient.
It is possible to separate the various components of whole blood either under or after centrifugation, due to their differing densities. Some prior art methods, such as that in U.S. Pat. No. 4,120,448, utilize a chamber connected to a centrifuge. The centrifuged blood separates in the chamber, and a plurality of collection means are positioned at various locations in the chamber corresponding to the areas where each component congregates, which is density-dependent.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
PATENT NO.ISSUE DATEINVENTOR4,120,448Oct. 17, 1978Cullis4,720,284Jan. 19, 1988McCartyDes. 314,824Feb. 19, 1991Moon5,674,173Oct. 7, 1997Hlavinka et al.5,723,050Mar. 3, 1998Unger et al.5,792,038Aug. 11, 1998Hlavinka5,921,950Jul. 13, 1999Toavs et al.6,315,706Nov. 13, 2001Unger et al.6,348,031Feb. 19, 2002Unger et al.6,652,475Nov. 25, 2003Sahines et al.WO95/01842Published: Jan. 15, 1995Unger
The prior art references listed above but not specifically described teach other devices for blood processing and further catalog the prior art of which the applicant is aware. These references diverge even more starkly from the reference specifically distinguished above.